The concept of modular design has a long history with numerous areas of application in furniture, building, etc. Modularity in construction allows mass production of prefabricated units adapted for ready assembly into substantially complete constructions. Modularity has been applied very productively in the furniture industry where preformed modules can be assembled, on site, to manufacture a wide range of furniture. An equally applicable area for modularity is building construction, either in a domestic or an industrial scale and a plethora of such modules have been designed and applied very productively.
The principle of modularity can be applied in a variety of aspects, for example, wall panels adapted to fit together for cladding purposes, floor panels, windows, doors, etc. Commonly the level of modularity is limited to a fixed range of components. However, a further level of modularity may see the same modules capable of forming a variety of components, for example, internal walls as well as floors, roof and ceiling, etc.
Clearly, if a given modular unit can perform a greater number of functions it is potentially able to increase cost and labour savings, and a large amount of innovation and design has been exercised in the development of such modular units. A key problem with multifunctional units is a concomitant loss of versatility of the units as the range of application increases. So, for example, a modular unit designed for internal wall construction only can be quite well adapted for this principle, but the same unit designed for external walls as well will usually be less well adapted for either task.
To date a fully universal modular building unit has not been developed which is capable of application to virtually all aspects of a given construction whilst retaining a suitable level of versatility. For example, the construction units disclosed in Australian Patent Applications 73336/81, 50573/79, 54804/86 and 23609/88 all display modular application but are limited to wall or partition application. Furthermore, units like AU50573/79 incorporate a highly specific asymmetric construction. AU73336/81 utilizes a complex connecting means and has an internal construction of limited strength and therefore limited application to a substantially vertical orientation. AU23609/88 discloses a more versatile system, however the construction suffers from limited torsional and horizontal strength and hence is limited to substantially vertical application.
More versatile units are described in Australian Patent Applications 77187/87 and 20952/88 and U.S. Pat. No. 3,236,014. All these disclosures detail panels suitable for modular building application albeit with limitations to universal application.
In particular, AU 77187/87 discloses a panel incorporating a laminate of core material with a skin material where the skin material has an integral connecting means moulded into the edge thereof. Such an inter-connecting method is clearly an advantageous development and capable of producing a strong and integral panel unit. However, such a design has limitations in the type of skin used in the laminate where only formable material can be used. Furthermore, the connecting method is fixed and incapable of modification.
Similarly, the disclosure in AU 20952/88 details a panel having a limited type of skin application coupled with a fixed type of connecting means incapable of modification.
U.S. Pat. No. 3,236,014 discloses a more highly versatile panel assembly Joint utilizing tongue and groove connecting means formed into a channel member, a core material and a laminated skin. Such a system offers the advantages of simple, strong connection between panels, a choice of core materials and a choice of skin materials. However, this disclosure fails to provide a fully universal modular unit capable of application to floors, walls and roof utilizing a simple system of connecting adaptors. The disclosure suffers from lack of modularity at the comer joint of walls and furthermore does not teach the use of one universal panel for floors, walls and roof.